Thursday 2 February 2012 17.00 EST
First published on Thursday 2 February 2012 17.00 EST

Politicians think about immigration differently from the rest of the population. For some people that difference will be easily explained – something along the lines of politicians preferring to ignore immigration, but the rest of us having to live with it. Actually, the reverse is the case. The truth is that politicians worry about immigration more than the rest of the population do, not less. That's because politicians take polls seriously, and the polls say that immigration is the second most important issue "facing the country". Tracker polls by YouGov regularly show this: the latest has the top three issues as the economy (82%), immigration (47%) and health (25%).

Ask voters for the most important issues "facing you and your family", on the other hand, and immigration drops well down the scale. On this more personal yardstick, closer to people's actual lived experience, the economy (69%) is still way out in front, but pensions (36%) is now second, with health (31%) third. Immigration only comes in joint seventh, behind tax, family life and education, and level pegging with crime. None of this means that immigration is not actually important, especially in some regions and to some voters. But the difference in the two scales may explain why politicians, always more conscious of national policy – and of the national press – than the more locally focused voters, give immigration such high priority. It may also suggest the "Blue Labour" assumption that strong communities and immigration are incompatible is not true in many cases.

The coalition government certainly treats immigration as a priority. Like Labour before, ministers are reacting to increasingly difficult political times by sharpening the focus on immigration. The immigration minister, Damian Green, made a well-trailed speech yesterday, setting out a policy based on allowing "the right numbers" and "the right people" into the UK. And it will not be long before the home secretary, Theresa May, confirms that ministers have decided to redesignate the majority of economic migrants in this country as "guest workers", along German lines, as well as putting tighter curbs on residents bringing in spouses from abroad to live here. As Mr Green again made clear yesterday, the main criterion for both groups will be based on income. Only migrants who earn at least £31,000 a year (and possibly as much as £49,000) will be able to settle here after their five years are up, and only those on around £26,000 will be able to marry someone from abroad.

There are several problems with this strategy. The overarching one is that it is an old-fashioned approach, based too much on broad brush numerical targets and insufficiently adaptive to modern migration practice – which is increasingly based on temporary stays not permanent settlement – as well as inadequately responsive to the effects of recession. Mr Green says, reasonably, that the immigration debate should move on from the single issue of numbers. Yet that is more easily said than done, since the government's headline goal has always been to bring net migration – UK immigration minus UK emigration – down to the "tens of thousands" by 2015. That is getting harder, because immigration has until recently remained at broadly the same level while emigration has dropped off. As a result, the gap widened to 252,000 in 2010. To meet the target, therefore, immigration will have to fall sharply or emigration surge, or both.